import java.util.ArrayList;
import java.util.List;

public class JavaTest {
    public static void main(String[] args) {
        String s = null;
        System.out.println(s);
        List<String> list = new ArrayList<>();
        for (int i = 0; i < 10; i++) {
            list.add(s);
        }

        for (String s1 : list) {
            System.out.println(s1);
        }
    }
}
